Ikenvapes are great also i have never had an issue with Boge's ether, some of the problem is most likely user error you should never get a burned taste if you have prepared the carto properly.
you cant just fill them up and start
vaping right away some depending on filler used take a good 20-30 minutes until all the filling is soaked and you dont want to use one until then.
it only takes one dry burn to ruin the carto,if you get a dry burn just toss the carto you just ruined it all the filler that was against the coil just burned away and it will never work good again.
here's how i prepare every carto i use:
i slowly add drops in the tip slowly spinning it watching to be sure it is getting absorbed and stopping from time to time until it soaks in so i dont flood it. then i slide it in my tank and fill the tank,then attach it to my ecig and take a few long hard draws(without firing the device) and watch for bubbles coming into the tank from the punch hole, then i let it sit for about 20 minutes standing upright.
after that i turn my voltage down about as low as it goes and try a super small hit(like half second) if there is any burnt flavor at all i ad more juice to the tip and take a few more draws to suck more juice into the carto and let it sit a few more minutes and try again.
once i get a quik draw that taste like my juice (usually first try) i crank up to my desired voltage and im good to go.
since doing it this way i waist alot less carto's think i had one bad one out of the last 50 i ordered and i use, Ikenvapes,Smok,boge's all with the same success.